Skip to Main Content

Latest News

May 17, 2010
Volume 88, Number 20
p. 12

Bacteria Chew Up Atrazine

Synthetic Biology: Engineered E. coli seek and destroy herbicide

Celia Arnaud

  • Print this article
  • Email the editor

Latest News



October 28, 2011

Speedy Homemade-Explosive Detector

Forensic Chemistry: A new method could increase the number of explosives detected by airport screeners.

Solar Panel Makers Cry Foul

Trade: U.S. companies complain of market dumping by China.

Novartis To Cut 2,000 Jobs

Layoffs follow similar moves by Amgen, AstraZeneca.

Nations Break Impasse On Waste

Environment: Ban to halt export of hazardous waste to developing world.

New Leader For Lawrence Livermore

Penrose (Parney) Albright will direct DOE national lab.

Hair Reveals Source Of People's Exposure To Mercury

Toxic Exposure: Mercury isotopes in human hair illuminate dietary and industrial sources.

Why The Long Fat?

Cancer Biochemistry: Mass spectrometry follows the metabolism of very long fatty acids in cancer cells.

Text Size A A

Chemists at Emory University have reprogrammed bacteria to seek and degrade the herbicide atrazine (Nat. Chem. Biol., DOI: 10.1038/nchembio.369). Such bacteria could prove useful for bioremediation of atrazine, which is toxic to animals and possibly humans as well.

Justin P. Gallivan, Joy Sinha, and Samuel J. Reyes engineer Escherichia coli to produce RNA molecules called riboswitches that change conformation when they bind atrazine. The switching activates the translation of a protein called CheZ that allows the bacteria to move and chase atrazine in their surroundings. “The riboswitch acts like a molecular brake,” Gallivan says. “When you add atrazine, you release the brake and the cells can move.”

The usual way to find riboswitches is to start with an RNA that tightly binds the target. “You can imagine some RNAs that might bind atrazine very well but be incapable of undergoing a conformational change that allows you to get a change in gene expression,” Gallivan says. He and his coworkers screened a library of RNAs with moderate affinity for atrazine to find the best riboswitch. “By doing in vivo selection, we can find switches that work the way we intend,” he says.

The team also rewired the bacteria to produce an enzyme that converts atrazine to hydroxyatrazine, which does not act as an herbicide and is not as toxic.

The riboswitch binds atrazine but not its degradation product. “If you’re chasing something nasty in the environment, you want to break it down and keep looking for more of the nasty thing rather than get hung up on the product,” Gallivan says.

“This work represents a clever use of riboswitches to engineer E. coli cells to show a chemotactic response to the herbicide atrazine,” says Lawrence P. Wackett, a biochemist at the University of Minnesota, who identified the enzymes that degrade atrazine. “It is currently unclear what advantage this offers in bioremediation applications, but it may be useful as a methodology for selecting atrazine-metabolizing clones with differential activity.”

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2011 American Chemical Society
  • Print this article
  • Email the editor

Services & Tools

ACS Resources

ACS is the leading employment source for recruiting scientific professionals. ACS Careers and C&EN Classifieds provide employers direct access to scientific talent both in print and online. Jobseekers | Employers

» Join ACS

Join more than 161,000 professionals in the chemical sciences world-wide, as a member of the American Chemical Society.
» Join Now!